JPH09255689A - Rearrangement of trichlorosilane - Google Patents

Abstract

(57) Abstract: A novel method for highly efficient redistribution of trichlorosilane to dichlorosilane is provided. SOLUTION: Trichlorosilane is redistributed in the presence of N, N, N ', N'-tetraethylethylenediamine (TEEDA) to form a complex of dichlorosilane and TEEDA. This dichlorosilane is later heated to T
It is dissociated from the EEDA and then used in standard processes that require dichlorosilane as a reactant or source material. Instead, this dichlorosilane and TEEDA
The complex containing is used as a reactant for hydrosilylation with an α, β-unsaturated olefinic nitrile, or is reacted with a Grignard-type reagent to make an organosilane.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to N, N, N ',
It relates to a method of redistributing trichlorosilane in the presence of N'-tetraethylethylenediamine (TEEDA) to form a complex containing dichlorosilane and TEEDA. This dichlorosilane is later dissociated from TEEDA by a method such as heating from TEEDA and then used in the standard process requiring dichlorosilane as a starting material or reactant. Alternatively, the complex containing the dichlorosilane and TEEDA is used as a reactant for the hydrosilylation of α, β-unsaturated olefinic nitriles or is reacted with Grignard type reagents to make organosilanes.

Such as the reaction of hydrogen chloride with granular silicon,
A typical process for the production of chlorosilanes yields a product that is predominantly trichlorosilane. The ability to redistribute trichlorosilane to dichlorosilane provides the flexibility to meet the needs for each of these chlorosilanes. Under typical uncatalyzed conditions, redistribution of trichlorosilane results in 15 mol% redistribution of trichlorosilane to dichlorosilane. The method of the invention surprisingly gives a redistribution of essentially 100 mol%. Therefore,
The method of the present invention is a more efficient method of redistributing trichlorosilane to dichlorosilane. Furthermore, the method of the present invention
It provides a complex containing dichlorosilane and TEEDA that is a solid and is easier and safer to handle than dichlorosilane, which is a gas under ambient conditions.

[0003]

BACKGROUND OF THE INVENTION It is known that certain nitrogen-containing compounds catalyze the redistribution of chlorohydrogensilanes. For example, US Pat. No. 3,044,845 teaches that dichlorosilane can be prepared from trichlorosilane by first forming a mixture of trichlorosilane, hexamethyltriaminotriazine and pyridine (or a hydrocarbon-substituted pyridine) as a catalyst. There is. Thereafter, a promoter for the catalyst, such as a liquid hydrocarbon in which trichlorosilane is soluble, is added to the mixture, and the resulting mixture is then heated.

US Pat. No. 4,038,371 claims redistributing trichlorosilane to dichlorosilane in the presence of a tetraalkylurea as a catalyst.

US Pat. No. 4,746,752 discloses (i) a quaternary ammonium salt or a quaternary phosphonium salt,
It is disclosed that silanes are redistributed in the presence of a catalyst containing (ii) a tertiary amine, or (iii) an ion exchange resin containing a tertiary amine group or a quaternary amine group.

US Pat. No. 5,026,533 shows that an alkylaminotrialkoxysilane chemically bonded to a support catalyzes the redistribution of trichlorosilane to dichlorosilane.

However, the technique quoted above is based on TE
It is not recognized that EDA redistributes trichlorosilane to form a complex containing dichlorosilane and TEEDA.

[0008]

The present invention is a method of redistributing trichlorosilane. In this method, (A) trichlorosilane is brought into contact with N, N, N ', N'-tetraethylethylenediamine, and dichlorosilane and N, N,
A complex containing N ', N'-tetraethylethylenediamine is formed, and (B) dichlorosilane and N, N,
Recovering the complex comprising N ', N'-tetraethylethylenediamine.

Carbon tetrachloride is also formed as a redistributed product of the process of this invention. This carbon tetrachloride is also recovered by standard methods such as distillation and subsequently used in standard processes that require carbon tetrachloride.

The process according to the invention can be carried out in the gas phase, but is preferably carried out in the liquid phase. The trichlorosilane is contacted with TEEDA in any standard reactor suitable for contacting the chlorosilane in mixture with the second reactant. The reactor can be, for example, a continuous stirred batch type reactor, a semi-batch type reactor or a continuous type reactor.

The process of the present invention is preferably carried out in an essentially anhydrous state. Therefore, it is beneficial to purge the reactor with a dry inert gas, such as nitrogen, to maintain a blanket of such gas in the reactor.

The molar ratio of trichlorosilane to TEEDA is not critical to the invention and can vary within wide limits. Generally, trichlorosilane vs. TE
A useful EDA molar ratio range is 0.1: 1 to 10: 1. Preferred is when the molar ratio of trichlorosilane to TEEDA is greater than stoichiometric. More preferred is a molar ratio of trichlorosilane to TEEDA of 2: 1.
When it is in the range of 5: 1.

The present invention is preferably carried out in the presence of organic solvents as diluents. Any organic solvent that does not interfere with the redistribution of trichlorosilane and the formation of the complex containing dichlorosilane and TEEDA can be used here.
The contact between trichlorosilane and TEEDA is preferably carried out in the presence of an organic solvent in which the complex containing dichlorosilane and TEEDA is also dissolved. Examples of organic solvents useful as diluents in the method of the present invention include dichloromethane and 1,2-dichloroethane. The preferred polar organic solvent used as a diluent is dichloromethane. The volume of the organic solvent used as the diluent ranges from the solvent-free state to twice or more the total volume of the total of trichlorosilane and TEEDA. Preferably, the volume of the organic solvent is 0.3 volume or equal volume of the total total volume of trichlorosilane and TEEDA.

The complex containing dichlorosilane and TEEDA is then recovered from this process. Recovery of this complex simply consists of storing it as it is when the reaction product was made. This complex has limited stability at room temperature and when exposed to air. However, in the absence of air and at low temperatures, this complex can exist stable for several weeks. In a preferred process, a second organic solvent is added after contacting trichlorosilane with TEEDA and in the presence or absence of a soluble organic solvent to precipitate a complex containing dichlorosilane and TEEDA from solution. Any organic solvent that precipitates the complex containing dichlorosilane and TEEDA and does not react with the complex can be used in the process of the invention. Useful organic solvents for the precipitation of this complex include, for example, pentane, hexane, and tetrahydrofuran. The preferred organic solvent for the precipitation of this complex is pentane.

In a preferred method, trichlorosilane is contacted with TEEDA in the presence of a diluting organic solvent such as dichloromethane at a molar ratio of trichlorosilane to TEEDA of 2: 1 to 5: 1, followed by a second. The complex of dichlorosilane and TEEDA is precipitated by the addition of an organic solvent such as pentane.

The process according to the invention can be carried out in the temperature range from 0 ° C. to the boiling point of trichlorosilane. Preference is given to when the process is carried out in the temperature range from 15 ° C to 30 ° C.

The complex containing dichlorosilane and TEEDA prepared by the method of the present invention is dissociated by heating, and dichlorosilane can be recovered from this complex. Then
This dichlorosilane is used in standard reactions and processes that require dichlorosilane as a starting material or reactant.

The complex of the present invention containing dichlorosilane and TEEDA can also be reacted with a Grignard type reagent represented by the general formula RMgCl (where R is an alkyl group or an aryl group). The R group can be methyl, ethyl, propyl, t-butyl or phenyl. The reaction of the complex containing dichlorosilane and TEEDA with the Grignard-type reagent is carried out by standard methods known in the art for reacting chlorosilane and Grignard-type reagents.

The complex containing dichlorosilane and TEEDA is further reacted with an α, β-unsaturated olefinic nitrile of the formula:

[0020]

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A cyanoalkylsilane (wherein each Y is independently selected from a hydrogen atom and a lower alkyl group having 1 to 8 carbon atoms) can be formed. The unsaturated olefinic nitrile is, for example, acrylonitrile, methacrylonitrile, crotononitrile, ethylacrylonitrile, 1-cyanobutene-1 or 2-cyanooctene-1. The dichlorosilane and TEEDA containing complex reacts with the α, β-unsaturated olefinic nitrile to form a cyanoalkylsilane at a temperature within the range of 0 ° C. to the dissociation temperature of the dichlorosilane and TEEDA containing complex. Preferred is when this reaction is carried out at a temperature in the range of 20 ° C to 50 ° C.

[0022]

【Example】

Example 1 Trichlorosilane redistributed in the presence of TEEDA and methylene chloride to give dichlorosilane and TEEDA.
Was evaluated for its ability to form. All reactions were performed in glass flasks under a blanket of dry nitrogen. Trichlorosilane was distilled before use. TEEDA was refluxed over CaH ₂ and then distilled. Dichloromethane was distilled from P ₂ O ₅ just before use. The volume of material placed in the flask is shown in Table 1. The materials were placed in the flask by syringe through a rubber septum.

Dichloromethane was first placed in the flask,
Then trichlorosilane was added. Then TEEDA
Was placed in a flask and the contents of the flask were cooled to room temperature.
The volumes of trichlorosilane, TEEDA and dichloromethane placed in the flask are also shown in Table 1. Pentane was then placed in a flask and the flask and its contents were -20
Stored at 16 ° C for 16 hours. The volume of pentane placed in the flask is shown in Table 1. A crystalline precipitate formed during the addition of pentane. After 16 hours, this liquid was removed from the precipitate.
The precipitate was found to have a melting point of 101-102 ° C. This precipitation is based on the following data: dichlorosilane and T
Identified as a complex of EEDA: ¹ H NMR
δ4.99 (s, 2H, SiH), δ2.91 (q,
8H, J = 7.2 Hz, CH ₂ CH ₃ ), δ 2.78
(S, 4H, CH ₂ CH ₂ ), δ1.13 (t, 12
_{H, J = 7.2z, CH 3} ); 13 C NMR 48.5
(Br, CH ₂ CH ₃ ), 47.57 (m, CH ₂ CH
₂ ), 10.0 (b, CH ₂ CH ₃ ); ²⁹ Si NMR
(−30 ° C.), δ−120.2 (d, ^J SiH = 40
4 H ₃ ).

The yield% of the complex containing dichlorosilane and TEEDA is shown in Table 1 as the percentage of the added TEEDA complexed with dichlorosilane.

The complex containing dichlorosilane and TEEDA was determined by X-ray analysis and was found to be a hexacoordinated adduct of dichlorosilane with both nitrogens of TEEDA chelating to silicon. This dichlorosilane and TEE
The DA-containing complex was found to be stable under nitrogen at room temperature for at least 2 months, soluble in dichloromethane and 1,2-dichloroethane, slightly soluble in tetrahydrofuran, and insoluble in pentane and hexane. It was

[0026] Table 1 formation of the complex comprising dichlorosilane and TEEDA by redistribution of trichlorosilane in the presence of _{TEEDA HSiCl 3 TEEDA HSiCl 3: TEEDA} CH 2 Cl 2 pentane yields mL m mol mL m mole mole ratio ml ml % 2.4 23.4 5.0 23.4 1: 1 15 16 17 0.8 8.0 1.7 8.0 1: 1 5 10 26 4.7 46.9 5.0 23.4 2: 1 15 25 50 28.4 281 20.0 93.8 3: 1 50 100 86 37.9 375 20.0 93.8 4: 1 50 100 98 17.0 169 9.0 42.2 4: 1 20 20 90 9.5 93.8 3.5 16.4 5.7: 1 10 10 94

Example 2 The ability of a complex containing dichlorosilane and TEEDA to hydrosilylate acrylonitrile was evaluated. In a dry box, the complex containing dichlorosilane and TEEDA prepared as described in Example 1 was placed in a 10 mL single neck flask. A rubber septum was attached to the mouth of the flask, and the flask was taken out of the drying box. Dichloromethane (4.0 mL) was placed in the flask to dissolve the complex containing dichlorosilane and TEEDA, then 0.18 mL of acrylonitrile was added. The reaction mixture was stirred at room temperature and samples withdrawn at the times shown in Table 2 for analysis by NMR. The% yield was calculated by integrating the acrylonitrile signal versus product peak. The column marked "% conversion" gives the% conversion of acrylonitrile to product. In Table 2, product A
Is Cl ₃ SiCH ₂ CH ₂ CN and the product B is Cl
₂ HSiCH ₂ CH ₂ CN and the product C is ClH ₂
SiCH ₂ CH ₂ CN.

[0028]

Example 3 The ability of a complex containing dichlorosilane and TEEDA to react with PhMgCl was evaluated. In a dry box, 3 g of the complex containing dichlorosilane and TEEDA prepared as described in Example 1 was placed in a 250 mL 2-neck flask. The flask was removed from the dry box and fitted with a stir bar, condenser and rubber septum. Then 10 mL CH ₂ Cl ₂ and 30 mL tetrahydrofuran were placed in the flask through the septum. 13.2
A Grignard-type reagent containing mL PhMgCl (Ph = phenyl) was placed in the flask over 5 minutes. The reaction was mixed overnight and then the solvent was removed by evaporation. Ether (30 mL) was added to dissolve the product, then HCl.
Is added to decompose unreacted starting material, and water-soluble TEEDA.
2HCl was formed. The resulting liquid mixture was extracted with ether and the extract was distilled to give a yield of 1.51 g Ph ₂ Si.
H ₂ was obtained. This identification was confirmed by ¹ H NMR and ²⁹ Si NM.
Measured at R.

Example 4 Separation of carbon tetrachloride from the reaction of trichlorosilane with TEEDA. A mixture consisting of 20 mL dichlorosilane and 11.4 mL trichlorosilane was formed in a 100 mL single neck flask. Then 6.0 mL
Of TEEDA was placed in the flask. Pentane (20
(mL) was placed in the flask and a crystalline precipitate formed.
After storage for 16 hours at -20 ° C, 5.7 g of precipitate was isolated and treated with dichlorosilane and TE by the method described in Example 1.
It was identified as a complex containing EDA. Volatiles were distilled from the liquid removed from the reaction flask. Pentane,
CH ₂ Cl ₂ and HSiCl ₃ were distilled from the collected volatiles, leaving 5.56 g of residual liquid. ¹ H of residual liquid
NMR and ²⁹ Si NMR show that the molar ratio is about 10
It was shown to contain 3: 38: 1 SiCl ₄ : CH ₂ Cl ₂ : pentane.

 ─────────────────────────────────────────────────── ———————————————————————————————————————————————— Inventor Stephen Doane Cruz, Minnesota 55317, Chanhassen, Sierra Court 7220

Claims (10)

[Claims] 1. A method for redistributing trichlorosilane comprising: (A) contacting trichlorosilane with N, N, N ', N'-tetraethylethylenediamine to obtain dichlorosilane and N, N, N', Forming a complex containing N'-tetraethylethylenediamine and recovering the complex containing (B) dichlorosilane and N, N, N ', N'-tetraethylethylenediamine. 2. The method of claim 1, wherein the method is performed in the liquid phase. 3. The molar ratio of trichlorosilane to N, N, N ', N'-tetraethylethylenediamine added to the process is in the range of 0.1: 1 to 10: 1.
Or the method of 2. 4. The trichlorosilane is added to N, N, N ',
The method according to claim 2, wherein N'-tetraethylethylenediamine is contacted with in the presence of an organic solvent selected from dichloromethane or 1,2-dichloroethane in which the resulting complex is dissolved. 5. The method of claim 4, wherein the volume of organic solvent added to the method is 0.3 volume to or equal to the total total volume of trichlorosilane and N, N, N ', N'-tetraethylethylenediamine. . 6. Dichlorosilane and N, N, N ', N'
The method according to claim 2, wherein the recovery of the complex containing tetraethylethylenediamine is carried out by precipitation with an organic solvent selected from the group consisting of hexane, pentane and tetrahydrofuran which precipitates the complex. 7. The trichlorosilane is treated with N, N, N ′, at a temperature in the range of 0 ° C. to the boiling point of trichlorosilane.
The method of claim 1 wherein the method is contacted with N'-tetraethylethylenediamine. 8. Dichlorosilane and N, N, N ', N'
A complex containing tetraethylethylenediamine is represented by the formula RM
A method for forming an organosilane, which comprises contacting with a reagent represented by gCl (wherein R is an alkyl group or an aryl group). 9. Dichlorosilane and N, N, N ', N'
A complex containing tetraethylethylenediamine, the formula YC
H = C (Y) CN (wherein each Y is independently selected from a hydrogen atom and a lower alkyl group having 1 to 8 carbon atoms) is contacted with an α, β-unsaturated olefinic nitrile. A method of forming a cyanoalkylsilane comprising. 10. The unsaturated olefinic nitrile is
Acrylonitrile, methacrylonitrile, crotononitrile, ethylacrylonitrile, 1-cyanobutene-1
And the method of claim 9 selected from the group consisting of 2-cyanooctene-1.